Valve lash is a clearance between a rocker arm and a valve stem of a valve assembly of an engine (e.g., an internal combustion engine (ICE)). Excessive (or abnormal) valve lash can reduce engine efficiency, increase engine vibration, damage valves, and cause other damage to the engine. Accordingly, monitoring valve lash can be useful in avoiding some of the above issues.
One attempt to monitor valve lash is disclosed in U.S. Patent Application Publication No. 2015/0370254 to Rivellini, filed on Jun. 22, 2015 (“the Rivellini reference”). In particular, the Rivellini reference describes a valve timing by deriving a cylinder head acceleration measurement via the vibration signal received by the knock sensor. In the Rivellini reference, the valve timing is monitored by deriving a valve lash based on a vibration signal, an engine crank angle, and a threshold valve lash model.
While the Rivellini reference uses a vibration signal to detect valve lash, the Rivellini reference does not describe features to accurately detect the valve lash and/or a magnitude of the valve lash based on a timing of the valve closing or a velocity associated with the valve closing.
The valve lash detector of the present disclosure solves one or more of the problems set forth above and/or other problems in the art.